(1) Field of the Invention
The present invention relates to the general field of packaging; more particularly, it relates to a new equipment structure for making a sealed pack tray formed by the assembling of an outer envelope, made of a relatively rigid material, such as cardboard, and an inner lining made of a thermoformed plastic film sealing the pack tray.
(2) Description of Related Art
In the dual component pack trays known to date, described for example in FR-2 826 937, the outer envelope is made integral with the inner plastic film through a gluing process, the glue being sprayed or projected on the inner face of said outer envelope.
Also, some glues of interest for assembling pack trays whose content is intended to be later cooked or reheated are difficult to apply through such a spraying method; that is the case, for example, for certain acrylic-type glues.
Moreover, a spraying process is not always clean and efficient. This glue application method generally results in soiling the surroundings, which is harmful to industrial production of the pack trays, in particular in the field of food-processing.